Starting device for electric motors.



PATENTED FEB. 12, 1907.

A. 0. KING.

STARTING DEVICE FOR ELECTRIC MOTORS.

APPLICATION FILED JUNE 9. 1806.

M 4 n v v V A 1 I, 11 I I Q I I I v I 2 INVENTUR. ARLHUR BRING.

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m 2 WW UNITED: era-res ARTHUR C, KING, OF MADlSQN, WISCGh SHT, ASSlG\ "R T N ORTHERlFl ELECTRICAL MANUFACTURlN COIVIZPANY, A CGLPORAllON 0F WIS- CONSIN. $TARTING Ho. 843,753. Specification. of Letters Patent. Patented Feb. 12, 1902 Application iilad Juno 9, 1908. Serial lie. 326,973.

To all whom i2; may concern.-

Be it known thatl, Anrnrm C. time, a

. citizen of the United States, residing at Madison, county of Dane, State of vyrscons' have invented certain new and useiul in:

provernents in Starting Devices for liilectric Motors, of which the following is a specification. 1

' This invention relates to devices for controllingelectric-motor circuits, and has for its ob3ect the provision of a device of this character which will protect the motor against accident due to careless hanohng and other causesin a reliable, safe, and eincicnt manner.

My invention relates more specifically to protective devices for electric-motor circuits.

As is well known, many motors are seriously injured by closing the armature-circuit with an open or very wcak'field. This mistake is often made even by experienced operators; and it is the object of my invention to positively prevent the occurrence of such accident.

In carrying out my invention 1 provide, in connection with the controlling-arm, which is biased to the off position, a latch or dog which normally abuts against a stud on the base, so as to prevent the movement of the arm toward running position. This dog is moved out of engagement with the stud by an armature controlled by a no-voltage magnet. When the field-circuit is closed and ,the no-voltage magnet is energized, the arm is free to be moved to the running position, and when it reaches this position the same armature which releases the restraining-dog locks the arm in running position.

in the accompanying drawing l have shown one embodiment of my invention; but it should be understood that this arrangement is merely typical and that many modistud 2.

segmental piece 11, acting as pawl ordo lne movement of the dog 11 with reference to part 8 is governed by a slot 12 in the dog, into which this a pin 1'3 in the part 8. 1; s ring is around the pivot 10 forces the seg mental dog 11 outward i'rom the pivot 5 llitO the position shown full lines in the raw- Soi'ta bly situated to cooperate with the starting-arm s is a no-voltage magnet 15, having a pivoted armatru'e 16, provincd with a spring arrn l7. "l'his armature is normally pressed away from the pole of the magnet by means of a spring 18-, made adjustable by means of the nut 19. The free end of the arm 17 is bent at right angles and provided with a 1:'shaped hea 20, adapted to it into the slot 9. lhis head is normally in engage ment with the dog ii. The magnet 3.5 is preferably connected the iield-circiut, so that the cirection of current will be from the positive main at 21, through the armature thence through wire esistance 3, arm l, and wire 2-4:, back to the line at 2 The field 26 is connected irom the main 21' at 27,

through the release-magnet ioyand back to line at The operation of. my device will be read ly understood from-the foregoing description. When it is desired to start the motor, the controlling-arm will he moved on to the against the stop 28 and further movement the arm cannot be made unless the magnet is energized. i When the magnet so energized, the armature 16, being attracted, moves the dog inward, so that when the arm is moved the dog will assume the position shown in dotted lines. The arinmay then be moved to the running position, the dog riding over the stop 28. When the arm reaches the running position, the head engages the slot 9 and locks the arm. Upon the weakening or breaking of the iield from any cause the armature is released, thereby releasin the arm, which returns to the off position.

it will thus be seen that l have provided an arrangement whereby it is impossible to in this position the dog 11 abuts many modifications Will suggest themselves to those skilled in the art. l 'or instance, the

arrangement will be such. that the locking means will not be accessible to the operator, and many other changes may be made Without departing from the spirit of my invention, the scope of which is set forth inthe annexed claims.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. A starting-rheostat, comprising a controlling-arm, a magnet responsive to predetermined decrease of excitation, and means controlled by said magnet for normally pre venting the movement 01 the arm to rimming pos tion.

2. A 'starting-rheostat, comprising a controlling-arm, a no-voltage magnet in the iield-eireuit,' and means controlled by said magnet for preventing the movement of said arm beyond the starting position.

3-. A starting-rheostat, comprising a controlling-arm, a no voltage magnet, and

. means in connection with said arm and con trolled by the magnet for preventing the movement of the arm to running position;

4. ll. startn'ig-rheostat, comprising a controlling-arin biased to oil' position and normally restrained against movement to running position, a no-voltage' magnet, and a single armature controlled thereby for releasing the restraining means and locking the arm in running position.

6. A starting rheostat, comprising eon trolling-arm biased to OH position and normally restrained against n'lovement to the running position, a no-voltage magnet, and a single armature controlled thereby and arranged to 'lirst release the restraining means. when said magnet is energized and then look the arm in running position.

In witness whereof I have hereunto set my hand this 6th day of June, 1906.

Altll'l U it C. KIN i'Vitnesses:

E. A. Lliirnnnen'r, F. M. Simmer). 

